On Mon, 28 Oct 2024, Steve Lewis via cctalk wrote:
Thomas,
Those images for the SHARP PC-5000 boot disk of MS-DOS 2.00 have worked
splendidly (at least the .IMD files, DiskImage is all I tried). I did have
to change the IMD Settings to Sides Two, Double-step On, and the 250kps to
300kps. I don't fully understand that last setting, but absolutely it was
necessary - the IMD image file wouldn't write to disk otherwise.
That is because you are writing "320K" disk in a 1.2M drive.
double step is to get 40 tracks instead of 80
a 160/180/320/360K drive spins at 300 RPM, and uses 250K data transfer
rate.
But, a 1.2M drive spins at 360 RPM, so you have to either change the drive
to 300 RPM at 250k, OR use the 360RPM at 300K
(some drives are dual speed; the FDC has a 300bps rate to compensatefor
those that are not.)
--
Grumpy Ol' Fred [email protected]
